Cadoni Enrico, Rosa-Gastaldo Daniele, Manicardi Alex, Mancin Fabrizio, Madder Annemieke
Organic and Biomimetic Chemistry Research Group, Department of Organic and Macromolecular Chemistry, Ghent University, Ghent, Belgium.
Dipartimento di Scienze Chimiche, Università di Padova, Padova, Italy.
Front Chem. 2020 Jan 23;8:4. doi: 10.3389/fchem.2020.00004. eCollection 2020.
The generation of PNA-decorated gold nanoparticles (AuNPs) has revealed to be more difficult as compared to the generation of DNA-functionalized ones. The less polar nature of this artificial nucleic acid system and the associated tendency of the neutral poly-amidic backbone to aspecifically adsorb onto the gold surface rather than forming a covalent bond through gold-thiol interaction, combined with the low solubility of PNAs itself, form the main limiting factors in the functionalization of AuNP. Here, we provide a convenient methodology that allows to easily conjugate PNAs to AuNP. Positively charged PNAs containing a masked furan moiety were immobilized via a double exchange Diels-Alder cycloaddition onto masked maleimide-functionalized AuNPs in a one-pot fashion. Conjugated PNA strands retain their ability to selectively hybridize with target DNA strands. Moreover, the duplexes resulting from hybridization can be detached through a retro-Diels-Alder reaction, thus allowing straightforward catch-and-release of specific nucleic acid targets.
与生成DNA功能化的金纳米颗粒（AuNPs）相比，生成PNA修饰的金纳米颗粒已显示出更为困难。这种人工核酸系统的极性较小，且中性聚酰胺主链具有非特异性吸附在金表面而非通过金-硫醇相互作用形成共价键的倾向，再加上PNA本身的低溶解度，构成了AuNP功能化的主要限制因素。在此，我们提供了一种简便的方法，可轻松地将PNA与AuNP偶联。含有被掩蔽呋喃部分的带正电荷PNA通过双交换狄尔斯-阿尔德环加成反应以一锅法固定在被掩蔽的马来酰亚胺功能化的AuNPs上。偶联的PNA链保留了与靶DNA链选择性杂交的能力。此外，杂交产生的双链体可通过逆狄尔斯-阿尔德反应解离，从而实现对特定核酸靶标的直接捕获和释放。
